The Danish forward curled a brilliant free kick from 25 yards that rattled into the top corner off the inside of the post with 28 minutes gone.

After going ahead, Spurs managed the game well, keeping possession in midfield for long periods and pressing the Blades high up the pitch.

United had little sight of the final third but went close three minutes from the break when McNulty’s first touch from a Stefan Scougall pass set him up for a volley which he hooked narrowly wide from the edge of the box.

It could have been even worse for United in the opening moments of the second period when Harry Kane found space for a shot ten yards out but pulled his low strike wide.

United enjoyed their best period of the game to that point after 55 minutes, pushing hard into opposition half without ever really having sight of goal.

Kane drilled a powerful free kick on target with 65 minutes gone but it did not trouble Mark Howard.

Ryan Mason was played into the area by Erik Lamela moments later but he put it wide under pressure.

Then the Blades surged into life, spurred on by the introduction of Adams who would quickly take centre stage.

First, Ryan Flynn’s low cross ran through to the youngster 15 yards out and he slammed a strike on the angle past Michel Vorm.

And moments later Adams struck again. After a scramble, the ball dropped for Adams and he fired home via a wicked deflection.

United made an excellent fist of winning the tie out right after Adams’ second.

Fellow substitute Louis Reed went close from the right corner of the box but fired over.

But then came a 87th minute suckerpunch.

Kane slid through a superb pass which Eriksen allowed to roll across his body before hooking the ball into the far corner.